The inventive concepts relate to methods of fabricating a metal nanowire dispersion solution and methods of fabricating a transparent conductor using the same and, more particularly, to methods of fabricating a metal nanowire dispersion solution having improved electrical characteristics and methods of fabricating a transparent conductor using the same.
A transparent conductor is optically transparent and electrically conductive material. The transparent conductor is widely used as transparent electrodes of a liquid crystal display device, a touch panel, an organic light emitting device and a photoelectric cell.
Metal nanowires may be used as a conductive material for forming the transparent conductor. The metal nanowire may be a wire-shaped nanostructure having a nanometer-scale size. A thickness or diameter of the metal nanowire may be in the range of about 10 nm to about 100 nm, and a length of the metal nanowire is not constrained but may be in the range of about 3 μm to about 100 μm. Thus, even though a few of metal nanowires are connected each other, the structure may have high electric conductivity and optical transparency of about 80% to about 90%.
However, it may be difficult to control shapes of the metal nanowires. Nanoparticles, nano-bars, or nano-clusters may be inevitably formed in a process of forming the metal nanowires. The nanoparticles may be globe-shaped, plate-shaped or polyhedron-shaped. The nano-bar may have a small ratio of a long axis to a short axis. The nano-clusters may be formed by aggregation of metal nanowires. As a result, a yield of the metal nanowires may be lowered.
On the other hand, the metal nanowires may be surrounded by an organic protection agent that is added in order to lead directional growth of the metal nanowires. Thus, a contact resistance between the metal nanowires may be increased due to the organic protection agent when the network is formed by the metal nanowires. As a result, it may be difficult to maintain the high electric conductivity of the nanowire network.